Typical Issues and Problems Related to UGM

UGM Issued and Problems

Planning Oriented
1. Land use planning and control for future locations of truck terminals
2. Site impact analysis of proposed locations for truck terminals
3. Zonning policies for truck space locations in CBD and suburbs
4. Economic and safety related regulations

Engineering and Design Oriented
1. Routing for large truck through urban areas
2. Routing for large trucks carrying hazardous material through urban areas
3. Design of of loading dock and access of aprons and ramps
4. Design of intersection with heavy truck
5. Curb space management for car loading and unloading

Urban Goods Movement Characteristics

Patterns of Truck Movement

• Based on the origin and destination of trips, truck movements can be divided into two categories. One is internal movement and other is external movement.
• Most of the internal movements are made by single unit truck.
• External movement can categorized into types - through movement and external - internal movement
• Through movement has not any significant effect on economic activities of urban area. It has only environmental impact on urban area.
• In the absence of adequate bypass route, 'through' trucks move along highway through the developed area which may cause serious noise and safety problem.
• External - internal movement has close relation with urban economic activities.
• Majority of freights is carried by trucks and rail in most cases.

Urban Goods Movement

Urban Good Movement (UGM) is essential aspect of urban transportation but the transportation planners have less attention on it. There are several reasons for lack attention towards UGM.

1. Planning guidelines and requirements issued by federal agencies have not been specific and strong for UGM
2. Private sector who bears many issues related to UGM problem have not been vocal
3. Consumers never force planners or elected officers to give attention for solving UGM problem
4. Planners and engineer working local agencies carry heavy work load and are too busy to spend time on UGM issues and problems
5. Transportation Engineering curriculum in universities do not cover properly UGM issue.

Roadway Capacity In Highway Design

Roadway Capacity depends on the traffic volume. Traffic volume can be served at each level of service are referred to as "Service flow rate".Once each level of service has been chosen for particular design, the corresponding service volume logically becomes the 'design service volume'. It indicates that if the traffic volume using the facility exceeds design service volume, the operating conditions of the roadway will be in inferior to the level of service. The level of service appropriate for various various type of roadways are given below:

	Type of Area and Appropriate Level of Service
Highway Type	Rural Level	Rural Rolling	Rural Mountainous	Urban and Suburban
Freeway	B	B	C	C
Arterial	B	B	C	C
Collector	C	C	D	D
Local	D	D	D	D

Level of service = General Operating Condition

A = Free Flow

B = Reasonably Free Flow

C = Stable Flow

D = Approaching Unstable Flow

E = Forced or breakdown flow.

Relationship of Traffic to Highway Design

The major traffic elements that influence highway design are:

• Average Daily Traffic and Annual Average Daily Traffic
• Design Hour Volume
• Directional Distribution
• Percentage of Trucks
• Design Speed

Both ADT and AADT are fundamental measures of traffic flow. To the designer, most significant measure of traffic volume is the design hour volume, a two-way value, which may be determined by multiplying by AADT by a proportional representative of the amount of traffic occurring during the peak hour for an average weekday. This proportional value, known as the K- factor, typically decreases as AADT increases. The value of K ranges between 0.09 and 0.10 for many highways.

Geometric Design of Highways- Design Criteria

There are several criteria for geometric design of highways. These criteria or factor effects in designing of highways. The criteria or factors are given below:

• Design Controls and Criteria
• Roadway Capacity
• Design Speed
• Amount of traffic
• Design Vehicle

Geometric Design of Highway- Design Control and Criteria

The elements of designs are influenced by a wide variety of design controls, engineering, criteria and project-specific objectives. The factors are given below-

• Traffic Safety Consideration
• Functional Classification of the roadway
• Projected traffic volume and composition
• Require Design Speed
• Multimodal needs of the surrounding community
• Topography of the surrounding land
• Capital Costs for construction
• Agency funding mechanisms
• Human Sensory Capacities of roadway users
• Vehicle size and performance characteristics
• Public involvement, review and comment
• Environmental Considerations
• Right-of-way impacts and costs

Driver Perception And Reaction

Driver perception and reaction time is defined as the interval between seeing, feeling or hearing a traffic or highway situation and making an initial response to what has been perceived.

Perception reaction time varies from less than .5 sec to 3 sec or more. Green Shields has indicated that, in general:

1. The speed of all forms of reaction varies from one person to another and from time to time in the same person.

2. Reaction time changes gradually with age, very young and very old people being slower in their reactions.

3. People generally react more quickly to very strong stimuli than to weak ones.

4. Complicated situation takes longer to react to than simple ones

5. A person's physical condition affects his reactions. For example, fatigue tens to lengthen a person's reaction time.

6. Distraction increases the time of all reaction except the reflex.